Zinc is a mineral you probably don’t think about often. And you certainly don’t worry about zinc deficiency. Zinc is actually a metal, kind of like iron, needed in tiny amounts for some pretty important functions in the body. It is referred to as a micro-mineral since the needs are so small. But, don’t discount this important mineral for overall health! It keeps the immune system functioning, heals wounds, and may even help prevent cancer. What a powerful little sucker!
What Does Zinc Do for the Body?
As we mentioned, you shouldn’t underestimate zinc’s power. It is involved in so many important functions in the body, including: (1):
- Helps enzymes activate. It is required to initiate the activity of over 100 enzymes, proteins responsible for triggering every action of your metabolism.
- Boosts immune function. Helps maintain a healthy immune system. This is why you see it in many cold medications and supplements (and it actually does work!).
- Heals wounds. Needed to heal from any injury or wound.
- Supports growth during pregnancy and childhood. Zinc is needed for proper development.
- Necessary for proper taste and smell. A deficiency can cause issues with taste and smell.
- Helps make new DNA, protein, and cells. Basically, helps the body repair itself correctly if needed.
As you can see this little mineral plays a major role in keeping you healthy. But, other than just its regular day to day functions, the benefits of zinc go even deeper.
Zinc has many other health benefits including helping prevent many illnesses and diseases. Some of these are related to its ability to act as an antioxidant, reducing damage from free-radicals and lowering inflammation. Many nutrients with the power to fight free radicals have been linked to being able to reduce the risk of chronic disease, so this isn’t really a surprise. For zinc specifically, a few of the health benefits include:
May Help Prevent Cancer
Like many other vitamins and minerals, zinc has anti-inflammatory and antioxidant qualities. The ability to fight free-radicals and reduce inflammation suggests that it could possibly reduce the risk of developing cancer. Additionally, it helps support healthy cell division and DNA, preventing mutations, which sometimes lead to tumor growth.
A 2007 study found that supplementation in older adults reduced markers of oxidative stress. Excessive oxidative stress causes damage to the body’s cells and DNA, and may be a cancer trigger. Zinc was also shown to reduce inflammation in the study participants, another underlying cause of many chronic diseases, including cancer (2). Although cancer has multiple causes, getting enough into your diet may help reduce your risk.
Boosts Immunity and Fights Colds
A deficiency has been linked to poor immune function, increasing your risk of catching every cold and sickness you’re exposed to. Zinc activates immune cells so they fight off any viruses or bacteria that try entering the body. Even a slight deficiency impacts the immune system and lowers immune function (3).
Many natural cold medications and supplements contain zinc because it actually helps prevent you from getting sick. Research has shown that it decreases the length and severity of colds if taken within 24-hours of the onset of symptoms. It is believed that it fights colds by preventing viruses and bacteria from attaching to the nasal passages and the cells of the body. This, in turn, prevents the virus from taking hold, preventing the spread of the illness (4).
Based on this evidence, grab some lozenges for when you feel an illness coming on. Even if you don’t want to take a supplement, it can’t hurt to bump up your intake of foods high in zinc during cold and flu season to keep you healthy.
Helps Maintain Eye Health
A common cause of age-related vision loss is a condition called macular degeneration (AMD). AMD is caused by damage to the retina, resulting in the loss of central vision and inability to see fine details. It is one of the most common causes of vision loss for aging populations.
High intakes of zinc and other antioxidants may help slow the development of macular degeneration and preserve vision later in life (5). Further research is required to determine the exact amount needed to protect the eyes and how it interacts with other antioxidants. But in the meantime, just be sure to eat plenty of foods high in zinc.
Regulates Blood Sugar
People with type 2 diabetes are at an increased risk for issues with zinc metabolism. Zinc is affected by this illness because it’s required for the processing and storage of insulin. Diabetes is an illness characterized by issues with the hormone insulin (6).
Although we cannot say zinc deficiency causes diabetes or vice versa, there is a connection between the two because of the impact it has on insulin. The important thing is to keep insulin functioning properly so that blood sugar can be maintained at normal level. Maintaining normal blood sugar can help prevent diabetes, control weight, and stabilize energy levels.
May Boost Fertility
One of zinc’s main roles boosting healthy reproductive function, DNA replication, and cell growth. All of these are necessary for fertilization to occur. It also supports the growth of the fetus during pregnancy. Not getting enough during pregnancy or while you are trying to conceive can lead to serious developmental problems, or difficulty getting pregnant at all.
Zinc also helps maintain healthy testosterone in men. A deficiency association includes low serum testosterone which can lead to low libido and impotence, impacting fertility. Even minor deficiencies improve with supplements, leading to improved testosterone levels (7).
Let’s see if you are getting enough each day…
How Much Do You Need?
Most people get enough; deficiencies aren’t super common, except in specific populations. The amount of zinc you need per day is based on age, gender, pregnancy and breastfeeding. The need increases as you age. Also, women who are pregnant and breastfeeding do need a bit more to support the growth of the baby.
The Institute of Medicine is responsible for determining the Dietary Reference Intakes (DRIs) that provide recommendations for how much of each nutrient you need. These are based on current research and designed to prevent deficiency in most people.
Below are the recommended amounts of zinc for each age group (8):
- 0-6 months: 2 mg/day
- 7-12 months: 3 mg/day
- 1-3 years old: 3 mg/day
- 4-8 years old: 5 mg/day
- 9-13 years old: 8 mg/day
- Males over 14 years old: 11 mg/day
- Females 14-18 years old: 9 mg/day
- Females 19 years older and up: 8 mg/day
Some studies show that older adults, particularly those over 60 years old, fall slightly below the recommended intake. This may be because older people tend to eat less meat as they age, particularly if they have difficulty chewing (9).
Overall, unless you avoid specific foods (which we will get to later) or have difficulty absorbing zinc, you likely get enough.
Symptoms of Zinc Deficiency
Never self-diagnose a vitamin or mineral deficiency without first speaking to a doctor. Many of these symptoms can be caused by a variety of different conditions. So, if you are experiencing any of these, talk to your doctor first before taking a supplement, as they can cause a few issues which we discuss a bit later.
Symptoms include (10):
- Poor growth or development
- Loss of appetite
- Hair loss
- Diarrhea or other digestive problems
- Impotence and lack of sexual function
- Eye and skin lesions
- Weight loss or gain
- Inability to heal wounds
- Taste and smell abnormalities
- Brain fog and mental slowness
- Frequent illness due to a poorly functioning immune system
Zinc deficiency is hard to measure with a blood test. A doctor can check the zinc levels in your plasma, but you can still have symptoms of zinc deficiency even if the levels are normal. Zinc is frequently located inside proteins, so it’s not possible for a blood test to measure how much you have in your body at any given time. If a doctor suspects a zinc deficiency, they often evaluate the person’s diet and overall health to try to determine the cause (11).
Zinc deficiency is pretty uncommon, particularly in the United States. Most people do get enough from their diet. Zinc deficiency usually only happens when there is inadequate absorption from food, even if you are eating high zinc foods. Or, if there is some type of increased requirement, or a loss of zinc occurring. It’s in a lot of foods, so if someone eats even a marginally diverse diet, they typically get enough (12).
Knowing this, there are a few groups of people that are more susceptible to zinc deficiency:
- People with digestive diseases. Those who have difficulty absorbing nutrients from food due to illnesses such as ulcerative colitis or Crohn’s disease are at risk for deficiency because their bodies are unable to get enough from the food they are eating.
- Vegetarians or vegans. You might be surprised because plant foods contain lots of zinc. But, it may not be properly absorbed from plant foods because of phytate, a plant compound that blocks absorption. Therefore, those following a plant-based diet should focus on eating about 50% more zinc than meat eaters. Certain food preparation methods such as soaking beans or legumes helps increase zinc availability (13).
- Pregnant or breastfeeding women. Zinc is necessary to support proper growth of the baby and the health of the mother, therefore needs go up. Also, it is not uncommon for women to experience an aversion to meat during pregnancy, reducing their overall intake. Prenatal vitamins help (14).
- Too much alcohol. Drinking too much alcohol decreases absorption of zinc, and metabolizing alcohol uses up zinc stores in the body, resulting in a deficiency. Also, people with alcoholism tend to not eat very much, which increases their risk of deficiency. About 30% of alcoholics have a zinc deficiency (15).
Symptoms of Too Much Zinc
Zinc is a micro-mineral, meaning it is only needed in very small quantities. Too much zinc can lead to a toxicity. Since the body cannot store excess zinc, toxicity is usually short-lived. Still, you don’t want to risk it, right?
The Institute of Medicine sets an upper limit for most vitamins and minerals to prevent toxicity. One thing to note, these upper limits are for supplements only, it isn’t possible to get a dangerous toxicity from food alone.
The upper limits for zinc are:
- 0-6 months: 4 mg
- 7-12 months: 5 mg
- 1-3 years old: 7 mg
- 4-8 years old: 12 mg
- 9-13 years old: 23 mg
- 14-18 years old: 34 mg
- 19 years and up: 40 mg
Most of the negative side effects from too much zinc happen in the short-term after a high dose. These symptoms include: nausea, diarrhea, abdominal cramps, and vomiting and usually happen within 30 minutes of taking the zinc supplement. Usually, these symptoms go away completely after stopping the supplements (16).
Nasal sprays that contain zinc do not cause an overt toxicity but are not recommended because they can interfere with a proper sense of taste and smell. If you do use a nasal spray with zinc, the symptoms will improve after a few hours.
Zinc cannot build up in your body since there is no place to store it. But, when taken long-term, zinc supplements can block the absorption of copper, a mineral that is just as important as zinc. This can suppress the immune system, lead to anemia, and impair the formation of new healthy cells (17). Limit zinc supplementation to only a few days, and only if you really need it to prevent a cold or if a doctor recommends it.
Foods High in Zinc
The best way to meet your body’s need for zinc is to eat foods that are a good source of this important mineral. Zinc is found in many different foods, particularly ones high in protein since it binds to the protein molecule. Oysters are the food highest in zinc, but they are not a common source of this mineral in most people’s diets. Red meat and chicken are the most common sources of zinc for most people since they are a primary source of protein.
Foods rich in zinc, include (18):
- Red meat
- Poultry: chicken, turkey
- Whole grains, oatmeal
- Nuts: cashews, almonds
- Fortified cereals
Zinc: An Important Mineral for Your Health
Zinc is probably not something you think about a lot, but it should be of concern if you are following a vegetarian or vegan diet or are pregnant or breastfeeding. If you do fall into either of those categories, a multivitamin or prenatal vitamin would be a good addition to your routine.
But, if you are not a vegetarian or pregnant (or a pregnant vegetarian?) it can still help reduce the severity or duration of the common cold or flu. Who wants to be sick, right? So, keep some zinc in your medicine cabinet for those times when you feel an illness coming on. It can give your immune system the boost it needs to help fight off infection and keep you healthy.